One of the issues of Steven Universe that results in a lot of head scratching is the apparent apathy of humanity towards the gems and all of the alien gem tech they left scattered across the planet. While it is possible to come up with reasons why humanity would have little interest in this treasure trove of advanced alien technology the one thing I would think they couldn't ignore is Lars.
Lars died. Then he was resurrected into a new form that can survive without the need for sustenance and may likely be immortal if Lion is any indication. Human medicine has been trying to defeat death since the first human died and yet no one has come knocking on Lars' door to invite him to the nearest medical facility for some painless ("we promise") medical experiments. At the very least I'd have thought Connie's mother, Priyanka, would want to take a look at him.
Then there's Steven, the one who performed this particular miracle. Why isn't he somewhere filling test tubes with tears and spit? Between Lars and Steven is the potential of an actual elixir of life. Why does no one seem to care about that?